Umatilla County Weather in December
Average highs run from 43°F on December 1 to 40°F on December 31, and lows from 29°F to 27°F. Normal precipitation for the month is 1.50 in over about 13 wet days.
December day by day
The normal high and low for each date, and the record, in °F.
- Normal low
- Normal high
- Record high
- Record low
December at a glance
- Average high
- 41°F
- Average low
- 28°F
- Precipitation
- 1.50 in
- Snowfall
- 5.4 in
- Record high
- 72°FDec 16, 2025
- Record low
- -6°FDec 16, 2008
- Chance of a freeze
- 100%
- Daylight
- 8 h 58 min to 8 h 46 min
- Cloud cover
- 73%
- Humidity
- 80%
- Dew point
- 26°F
- Wind
- 10.5 mph
Every day of the month
A wet day has at least 0.01 inch of precipitation; snow means at least 0.1 inch of snowfall.
| Date | Normal high | Normal low | Record high | Record low | Chance wet | Chance of snow |
|---|---|---|---|---|---|---|
| Dec 1 | 43°F | 29°F | 59°F 2012 | 6°F 2014 | 41% | 9% |
| Dec 2 | 43°F | 29°F | 69°F 2021 | 17°F 2014 | 41% | 9% |
| Dec 3 | 43°F | 29°F | 63°F 2007 | 17°F 2011 | 41% | 9% |
| Dec 4 | 42°F | 29°F | 62°F 2007 | 11°F 2013 | 41% | 10% |
| Dec 5 | 42°F | 29°F | 65°F 2023 | 6°F 2013 | 41% | 10% |
| Dec 6 | 42°F | 29°F | 65°F 2023 | 3°F 2013 | 41% | 10% |
| Dec 7 | 42°F | 28°F | 60°F 2015 | 3°F 2013 | 41% | 10% |
| Dec 8 | 42°F | 28°F | 63°F 2015 | -3°F 2013 | 41% | 11% |
| Dec 9 | 41°F | 28°F | 66°F 2015 | 0°F 2013 | 41% | 11% |
| Dec 10 | 41°F | 28°F | 64°F 2004 | 0°F 2009 | 41% | 11% |
| Dec 11 | 41°F | 28°F | 66°F 2025 | 3°F 2009 | 41% | 11% |
| Dec 12 | 41°F | 28°F | 65°F 2014 | 10°F 2005 | 41% | 11% |
| Dec 13 | 41°F | 28°F | 61°F 2025 | 14°F 2005 | 41% | 12% |
| Dec 14 | 41°F | 27°F | 63°F 2025 | 8°F 2008 | 41% | 12% |
| Dec 15 | 40°F | 27°F | 63°F 2025 | 7°F 2008 | 41% | 12% |
| Dec 16 | 40°F | 27°F | 72°F 2025 | -6°F 2008 | 41% | 12% |
| Dec 17 | 40°F | 27°F | 63°F 2025 | -1°F 2008 | 41% | 12% |
| Dec 18 | 40°F | 27°F | 60°F 2024 | 7°F 2016 | 41% | 12% |
| Dec 19 | 40°F | 27°F | 59°F 2025 | 9°F 2008 | 41% | 12% |
| Dec 20 | 40°F | 27°F | 62°F 2017 | 1°F 2008 | 41% | 12% |
| Dec 21 | 40°F | 27°F | 60°F 2014 | 2°F 2008 | 41% | 12% |
| Dec 22 | 40°F | 27°F | 66°F 2020 | 0°F 2022 | 41% | 12% |
| Dec 23 | 40°F | 27°F | 56°F 2025 | 3°F 2022 | 41% | 12% |
| Dec 24 | 40°F | 27°F | 62°F 2005 | 1°F 2017 | 41% | 12% |
| Dec 25 | 40°F | 27°F | 60°F 2025 | 7°F 2017 | 41% | 12% |
| Dec 26 | 40°F | 27°F | 51°F 2005 | 17°F 2017 | 41% | 12% |
| Dec 27 | 40°F | 27°F | 56°F 2022 | 12°F 2021 | 41% | 12% |
| Dec 28 | 40°F | 27°F | 59°F 2022 | 12°F 2021 | 41% | 12% |
| Dec 29 | 40°F | 27°F | 58°F 2011 | 11°F 2021 | 41% | 12% |
| Dec 30 | 40°F | 27°F | 54°F 2018 | 3°F 2021 | 41% | 12% |
| Dec 31 | 40°F | 27°F | 51°F 2005 | 6°F 2014 | 41% | 12% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (PST).
- December 1
- sunrise 7:15 AM, sunset 4:13 PM
- December 31
- sunrise 7:35 AM, sunset 4:21 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USW00024155 (Pendleton), public domain. Records: NOAA GHCN-Daily, station USC00356550, every year on file, quality-flagged values removed. Cloud, humidity, wind and sunshine: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-24. Sun and moon: computed with the NOAA solar equations and Meeus.